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Quick answer
We found seven robot mowers on sale in the US that cut as high as 4 inches: the Segway Navimow X4 (0.75 to 4 in) and X3 (2 to 4 in), the Mammotion LUBA 3 AWD H and LUBA mini 2 AWD H (2.2 to 4.0 in), the Sunseeker X7 (0.8 to 4.0 in), and the Husqvarna Automower 410 iQ and 420 iQ (1 to 4 in). Those suit standard St. Augustine (3.5 to 4 inches, per UF/IFAS), Bahia and summer tall fescue. Many popular robot mowers stop below 3 inches, so check the height before you buy.
Robot mowers were designed in Europe for fine lawns kept short, and many still top out at 2.4 to 2.8 inches. That’s fine for bermuda, zoysia and centipede. It’s a problem for the tall-cut grasses that cover much of the South and the transition zone, where the right mowing height is 3 to 4 inches.
This list covers every robot mower we found on sale in the US that reaches 4 inches, the near misses, and an interesting UF/IFAS finding that robot mowers may let you cut St. Augustine lower than you think. Specs come from each brand’s US pages. MowReview quotes no prices and hasn’t tested these mowers. How we research explains why.
Which grasses need 4 inches
| Grass | Recommended height | Source |
|---|---|---|
| St. Augustine (standard cultivars such as Floratam) | 3.5 to 4 in | UF/IFAS |
| St. Augustine (dwarf cultivars such as Seville) | 2 to 2.5 in | UF/IFAS |
| Bahia | 3 to 4 in | UF/IFAS |
| Tall fescue | 3 to 4 in, higher in summer | University of Maryland |
You may not need the full 4 inches
UF/IFAS’s St. Augustine guide says robotic mowers “can tolerate lower heights because they remove small amounts of leaf blade frequently,” and that UF research kept Floratam at 2.4 inches year-round with no negative effects. A 4-inch robot still gives you room to cut higher in shade and drought, which UF/IFAS also recommends. Robot mowers for St. Augustine covers this in detail.
The seven that reach 4 inches
| Model | Cutting height | Stated slope | Stated coverage | Drive |
|---|---|---|---|---|
| Segway Navimow X4 | 0.75 to 4 in | 84% | 1.0 or 1.5 acres | Four-wheel |
| Segway Navimow X3 | 2 to 4 in | 50% | 1.0, 1.5 or 2.5 acres | Rear-wheel |
| Mammotion LUBA 3 AWD H | 2.2 to 4.0 in | 80% | 0.37, 0.75 or 1.25 acres | All-wheel |
| Mammotion LUBA mini 2 AWD H | 2.2 to 4.0 in | 80% | 0.37 acre | All-wheel |
| Sunseeker X7 | 0.8 to 4.0 in | 70% | Varies by version | All-wheel |
| Husqvarna Automower 420 iQ | 1 to 4 in | 45% | Up to 1 acre | Not AWD |
| Husqvarna Automower 410 iQ | 1 to 4 in | 45% (15% at boundary) | 0.5 acre | Not AWD |
Sources: Segway Navimow, Mammotion, Sunseeker and Husqvarna US product pages; Tractor Supply for the 420 iQ. Husqvarna doesn’t state the iQ drive type, but its 410 iQ accessory list describes the model as non-AWD.
1. Segway Navimow X4: the widest range
From 0.75 to 4 inches in quarter-inch steps, the X4 covers almost any US grass, and PCWorld tested it at both 3 and 4 inches. It also has the steepest slope rating of any wheeled robot we found, at 84%. It’s a large mower for lawns of an acre or more.
2. Segway Navimow X3: tall cuts on bigger, flatter lawns
The X3’s range starts at 2 inches and tops out at 4, which makes it a natural fit for St. Augustine, Bahia and tall fescue but not for bermuda. It comes in three sizes up to 2.5 acres. Navimow X330 vs X350 vs X390 explains the sizes.
3. Mammotion LUBA 3 AWD H: tall cuts on steep lawns
The H version of Mammotion’s flagship, rated for 80% slopes. Only the H reaches 4 inches; the standard LUBA 3 AWD stops at 2.7, and the two can’t be converted. LUBA 3 AWD vs LUBA 3 AWD H explains how to tell them apart on a listing.
4. Mammotion LUBA mini 2 AWD H: tall cuts on small lawns
The only 4-inch option we found sized for small lawns, at 0.37 acre on the 1500H. Again, it’s the H version you need: the standard LUBA mini 2 AWD cuts 0.8 to 2.6 inches.
5. Sunseeker X7: AWD and a broad range
Sunseeker lists the X7 at 0.8 to 4.0 inches with all-wheel drive and a 70% slope rating, so like the Navimow X4 it can handle both short and tall grasses.
6 and 7. Husqvarna Automower 420 iQ and 410 iQ: 4 inches from Husqvarna
Husqvarna’s wire-free iQ models reach 4 inches, unlike its AWD Automowers, which stop at 2.8. Husqvarna lists the 410 iQ at 0.5 acre and 45% slopes inside the lawn, and Tractor Supply lists the 420 iQ at up to 1 acre. Both use Husqvarna’s EPOS satellite positioning.
The near misses
| Model | Maximum height | Good enough for |
|---|---|---|
| Dreame A3 AWD Pro | 3.9 in | Nearly everything a 4-inch mower is |
| Segway Navimow i-series (i105N, i110N) | 3.6 in | Tall fescue in spring and fall; St. Augustine at the lower end of its range |
| Ecovacs GOAT A3000 LiDAR Pro | 3.54 in | Most tall fescue and Bahia heights |
| Mammotion YUKA mini 2 1000H | 3.5 in | Bluegrass, dwarf St. Augustine |
| Husqvarna Automower 435X AWD and 435 iQ AWD | 2.8 in | Bluegrass and fine fescue, not tall-cut grasses |
Sources: Dreame, Segway Navimow, Ecovacs, Mammotion and Husqvarna US product pages.
Watch the listing
On Amazon and big-box sites, Mammotion’s standard and H versions often appear side by side with near-identical photos. The model number (3000 vs 3000H) and the height range in the title are the giveaways. If a listing doesn’t state the cutting height, confirm it before you order.
The picks
For larger, gentle tall-cut lawns
Segway Navimow X3 (X330, X350, X390)
- Cutting height2 to 4 in
- Stated slope50%
- Stated coverage1.0 to 2.5 acres
A range that starts where tall-cut grasses start, three sizes up to 2.5 acres, and built-in 4G with a free period that runs up to five years on the X390.
Good for
- St. Augustine, Bahia and tall fescue lawns
- Large lots with moderate slopes
Less good for
- Bermuda or zoysia: it can’t cut below 2 inches
- Cross-slopes: PCWorld found the X350 unpredictable across slopes
- Rough ground: TechRadar said it’s not for especially rough terrain
For small tall-cut lawns, with slopes
Mammotion LUBA mini 2 AWD 1500H
- Cutting height2.2 to 4.0 in
- Stated slope80%
- Stated coverage0.37 acre
The small-lawn answer for St. Augustine and tall fescue, with all-wheel drive, built-in 4G and an edge disc that Mammotion says mows to about 2.1 inches from walls.
Good for
- Small St. Augustine and tall fescue lawns
- Small lawns with slopes
Less good for
- Wet grass: Techaeris found clippings build up underneath
- Gaps under 27 inches between zones
- Mismatched edges: Techaeris found the edge disc is fixed at about 2.6 inches
Husqvarna’s 4-inch option
Husqvarna Automower 410 iQ
- Cutting height1 to 4 in, electric
- Stated coverage0.5 acre
- ConnectivityCellular, Wi-Fi and Bluetooth
A wire-free Automower that covers short and tall grasses, with Husqvarna’s EPOS reference station included where Husqvarna Cloud positioning isn’t available. Husqvarna’s support pages say Automower Connect has no running costs.
Good for
- Half-acre lawns of any common US grass
- Owners who want Husqvarna’s dealer support
Less good for
- Steep edges: Husqvarna rates it at 15% at the boundary
- Complicated shapes: Husqvarna rates irregular lawns at 0.25 acre
- Steep lawns: 45% inside the lawn, below the AWD models
Questions
Which robot mowers cut 4 inches high?
We found seven US models with a stated maximum of 4 inches: the Segway Navimow X4 and X3, the Mammotion LUBA 3 AWD H and LUBA mini 2 AWD H, the Sunseeker X7, and the Husqvarna Automower 410 iQ and 420 iQ.
Which grasses need a 4-inch cutting height?
UF/IFAS recommends 3.5 to 4 inches for standard St. Augustine cultivars and 3 to 4 inches for Bahia. Extension services recommend 3 to 4 inches for tall fescue, at the higher end in summer.
Can a robot mower cut St. Augustine lower than 4 inches?
Possibly. UF/IFAS says robotic mowers can tolerate lower heights because they remove small amounts of leaf often, and its research kept Floratam St. Augustine at 2.4 inches year-round with no negative effects. Still, UF/IFAS recommends 3.5 to 4 inches for standard cultivars mowed conventionally.
Which robot mowers almost reach 4 inches?
The Dreame A3 AWD Pro reaches 3.9 inches, the Navimow i-series 3.6 inches, the Mammotion YUKA mini 2 3.5 inches and the Ecovacs GOAT A3000 LiDAR Pro 3.54 inches. Husqvarna’s AWD Automowers stop at 2.8 inches.
Is there a robot mower that cuts both tall and short grass?
The Navimow X4 has the widest range we found, 0.75 to 4 inches, and the Sunseeker X7 lists 0.8 to 4.0 inches. Mammotion splits its range across two versions, standard and H, so you must choose one.
Can a robot mower cut grass that has grown taller than 4 inches?
Not reliably. Robot mowers are designed to trim a little often, not to cut long grass down. Mow overgrown grass with a regular mower first, then let the robot maintain it.
The short version
If your grass is standard St. Augustine, Bahia or summer tall fescue, check the maximum cutting height before anything else. The Navimow X4 and Sunseeker X7 cover the widest range, the Navimow X3 suits big gentle lawns, the LUBA 3 AWD H and LUBA mini 2 AWD H suit slopes, and Husqvarna’s 410 iQ and 420 iQ are its 4-inch options. Just short of 4 inches, the Dreame A3 AWD Pro at 3.9 inches is close enough for most lawns.
Find the right mower for your grass
Grass-by-grass guides with extension mowing heights.
